[aduncan81]

I'm in the process of installing a paver patio (12'x23') to extend off of my covered patio. I've completed about 2/3 of the excavation (red clay) down to 6" under grade. The bottom set of string in the pictures is for a 4" drop along the 2 12' sections. The pavers are 2" thick with and will sit with 1" below grade and 1" above (touching the string) and the other 5" excavated for the 4" base and 1" sand.

Last night when I ran the strings and levels it turns out that the grade at the right side far corner is about 11" below the grade of the 2 corners against the existing covered patio. The left far corner is about 4" below but this was expected since I would be sloping the patio 3-4" away from the house anyways for drainage.

I did some research last night to find out the best way to close the 7" gap on the far right corner and a portion of the adjacent sides. I'm thinking of using 2 rows of matching 4" high wall block (with the bottom row partially below grade and on base material) to make the blocks level with the sand. Then when I lay my pavers, the ones that would go onto of the wall block would be secured with wall adhesive. Would this work?

I live in Georgia and will be using 6"x6" and 6"x9" pavers in a random running board pattern. Thanks!

 

[CoachDave]

Howdy ADuncan81,

It sure looks like you've got your work cut out for you. All the ideas you listed like the sloping and sand are sound paving practices. I didn't notice the depth of the paver base was listed. You need a solid foundation to keep things from shifting. The only thing I do not think will work is the adhesive idea. If you have an edging/border that is anchored in the ground the simple physics shows it will stay put. Weather has a way of destroying shortcuts. Other than that, as far as I can tell it would work well.
Hope this helps you in your project,
Coach Dave

 

[aduncan81]

Thanks DaveCoach. I think you may have misread where I was thinking of using the adhesives. The wall blocks will be even with the sand and most pavers will be set in the sand as usual but the pavers along the raised edges will have to be secured somehow to the top of the wall blocks. I was thinking that masonry adhesive would be the way to go but am open to suggestions. Otherwise, if they're not secured somehow, they'd easily be knocked off. Do you think this would hold?

The wall blocks should be fine as they are 30 pounds each and the bottom row will be mostly below grade.

I finished the digging last night, just putting the finishing touches on the drain trench and should be laying the base this weekend.
Thanks!

 

[aduncan81]

Here's a picture of my current status. Clay excavation is complete, trench drain added in middle of low side, geotextle fabric placed and #5 base material going in. Basically from the same view as the first picture.

I started adding the wall blocks to the low corner last night making sure that they are level and the 2nd row is 2" below the string line so that the pavers will be level when placed on top. Masonry adhesive between each block. Because the blocks are not rectanglar, there are large gaps between them at the joints (especially on the interior side). Before I backfill behind the blocks with the rest of my base material should these be filled with mortar of some sort?

Any other suggestions before I get too far along?
Thanks

 

[aduncan81]

Is this an active message board? Only 1 response in 10 days

 

[bob22]

A lot of people get distracted by summer and fun. You also seem to have a pretty good sense of what you are doing.
I haven't done what you are doing but a question or two:
1. Have you compacted the base material before placing block? I would think this should be done to prevent future settling issues.
2. "Before I backfill behind the blocks with the rest of my base material should these be filled with mortar of some sort?"
I wouldn't think that would be needed as the adhesive is pretty strong but I guess it wouldn't hurt; may be just a needless addition of work and expense. What purpose would it serve?

 

[aduncan81]

Thanks Bob. Yes, I compacted the base area under the blocks prior to laying them.

Regarding the mortar question, I was concerned with some of the base possibly spilling out of the gaps between the blocks. The blocks are a trapezoid like shape with rounded corners so the gap at the corners where 2 blocks meet is about 1" or so wide.

Also, I've got about 3-4" of #5 gravel (classifed as 3/4" but probably closer to 1" size) base down and compacted. It looks like I'll have another 2-3" of base to put down and was thinking of using #7 gravel (1/2" size) to finish out my base since this would compact tighter and less sand would fall through. Any thoughts on using a slightly smaller material for the top layer of base?
Thanks!

 

[bob22]

You might try posting your question in the Construction forum where some of the concrete experts are heard from. They've likely the experience on your base material questions. Unsure if they visit this forum.

 

[tayna]

I am getting ready to do a paver patio and a friend swears by putting crushed limestone on top of gravel, wetting and tamping before putting down the sand. He says the limestone kind of sets up like concrete and the sand doesn't go through. Good luck

 

[cibula11]

Thanks Bob. Yes, I compacted the base area under the blocks prior to laying them.

Regarding the mortar question, I was concerned with some of the base possibly spilling out of the gaps between the blocks. The blocks are a trapezoid like shape with rounded corners so the gap at the corners where 2 blocks meet is about 1" or so wide.

Also, I've got about 3-4" of #5 gravel (classifed as 3/4" but probably closer to 1" size) base down and compacted. It looks like I'll have another 2-3" of base to put down and was thinking of using #7 gravel (1/2" size) to finish out my base since this would compact tighter and less sand would fall through. Any thoughts on using a slightly smaller material for the top layer of base?
Thanks!

Limestone with screenings is what we use in Iowa. It has to have screenings or dust like material, to pack. If it's just gravel it will move and shift. You'll know if you have the right stuff if after you pack it with a plate compactor it is solid and can't be kicked around. As you run the plate compactor, spray and dampen with water. This makes the surface like concrete.